Manchester Memoir s^ Vol. xlvii. (1903), No. <J. 7 



monograph is illustrated with very beautiful coloured 

 plates, which are designed to show the influence of various 

 agents in bringing about the formation of indigo in the 

 leaves of this plant. 



During the last {&,\ years of his life Dr. Schunck 

 devoted his energies to investigating the great problem of 

 the nature of chlorophyll, the colouring matter which 

 occurs in the green leaves of plants, and which plays such 

 an all-important part in their development. Partly alone 

 and partly in conjunction with Dr. Marchlewski, he 

 published probably the most important papers which 

 have appeared on this difficult subject. These papers 

 contain the description of the best method yet devised for 

 preparing chlorophyll, and there can be no doubt that 

 this method, if it does not yield the pure colouring matter, 

 certainly enables it to be prepared in a much purer 

 condition than it was ever obtained before. In possession 

 of this highly purified product, Schunck and Marchlewski 

 submitted chlorophyll to a careful spectroscopical exami- 

 nation, and at the same time studied its chemical properties, 

 and made a most valuable investigation into the nature ot 

 the highly important products which are obtained when 

 chlorophyll is submitted to the action of reagents. From 

 the point of view of the future possibility of determining 

 the actual constitution of chlorophyll, the experiments on 

 the preparation of phylloxanthin, phyllocyanin, and the 

 beautifully crystalline phyllotaonin, and the examination 

 of their properties and mapping out of their absorption 

 spectra, indicate that there is a possibility of acquiring a 

 clear insight into the nature of the colouring matter at a 

 not far distant date. 



But probably the most far-reaching result which was 

 obtained, certainly from a biological point of view, is 

 the proof that pkylloporphyrin — a crystalline substance 



